Organic Semiconductor Centre, EaStCHEM School of Chemistry, University of St Andrews, Fife, KY16 9ST, St Andrews, UK.
Organic Semiconductor Centre, SUPA School of Physics and Astronomy, University of St Andrews, KY16 9SS, St Andrews, UK.
Angew Chem Int Ed Engl. 2022 Dec 23;61(52):e202213697. doi: 10.1002/anie.202213697. Epub 2022 Nov 23.
Herein, we demonstrate how judicious selection of the donor decorating a central multi-resonant thermally activated delayed fluorescence (MR-TADF) core based on DiKTa can lead to very high-performance OLEDs. By decorating the DiKTa core with triphenylamine (TPA) and diphenylamine (DPA), 3TPA-DiKTa and 3DPA-DiKTa exhibit bright, narrowband green and red emission in doped films, respectively. The OLEDs based on these emitters showed record-high performance for this family of emitters with maximum external quantum efficiencies (EQE ) of 30.8 % for 3TPA-DiKTa at λ of 551 nm and 16.7 % for 3DPA-DiKTa at λ =613 nm. The efficiency roll-off in the OLEDs was improved significantly by using 4CzIPN as an assistant dopant in hyperfluorescence (HF) devices. The outstanding device performance has been attributed to preferential horizontal orientation of the transition dipole moments of 3TPA-DiKTa and 3DPA-DiKTa.
在此，我们展示了如何明智地选择供体来修饰基于 DiKTa 的中心多共振热激活延迟荧光（MR-TADF）核，从而获得高性能 OLED。通过用三苯胺（TPA）和二苯胺（DPA）修饰 DiKTa 核，3TPA-DiKTa 和 3DPA-DiKTa 在掺杂薄膜中分别显示出明亮的、窄带的绿光和红光发射。基于这些发射器的 OLED 为该系列发射器实现了创纪录的高性能，其中 3TPA-DiKTa 在 λ 为 551nm 时的最大外量子效率（EQE）为 30.8%，3DPA-DiKTa 在 λ =613nm 时的最大外量子效率（EQE）为 16.7%。通过在超荧光（HF）器件中使用 4CzIPN 作为辅助掺杂剂，显著改善了 OLED 中的效率滚降。卓越的器件性能归因于 3TPA-DiKTa 和 3DPA-DiKTa 的跃迁偶极矩优先呈现水平取向。
